Electrical regulating apparatus



2 Sheets-Sheet 1.

(No Model.)

1-1. J. CONANT. l ELECTRICAL REGULATING APPARATUS, No. 414,191. Patented NovI 5, 1889E Wit eases. ZY/ Taf/071 (No Model.) 2 sheets-sheet 2. H. J. CONANT.

ELECTRICAL RBGULATING APPARATUS.

N0. 414,191. I Patented Nov. 5, 1889.

Wnesse. Inn/anton UNITED i ASTATES PATENT OFFICE. v

HENRY J. CONANT, OF V-ATERTOWN, MASSACHUSETTS. y

ELECTRICAL REG ULATING APPARATUS.

SPECIFICATIQN forming part of Lett-ers Patent No. 414,191, dated November 5, 1889. Application noa 'Fanny e, rasa. seria No. 298,790. (No model.)

To ad whom it may concern:

Be itknown that I, HENRY J. CoNANr, residing at Watertown, in the county of Middlesex and State of Massachusetts, have invented certain Improvements in Electrical Regulating or Governing Apparatuaof which the following is a specification.

This invention relates to electric regulators' or governors, and by it the fluctuations of a current traversing a main electric circuit are caused to automatically control, rectify, or

modify the speed of mechanism, and this reguto the conditions at any moment of the said work, which changes are,through the agency of suitable mechanism, made to controlthe speed of the engine, machine, or motor performing the work, the speed being thereby controlled and regulated automatically and promptly, so that when the work is progressing too fast or far, the speed of operation is retarded, while when the work is being done too sluggishly the speed, and consequently the rate of Work, is accelerated. It will be seen, therefore, that my regulator is both a current and a speed regulator, since fluctuations of the current may produce correspondingiiuctuations in speed, which act upon the original source of electrical energy, increasing or decreasing the electro-motive force, as the case may be, or may alternatively produce fluctu ations or adjustments of speed aiecting directly the work which is being performed.

More specifically, in one embodiment of my invention which I have shown and described, in which an electric-lighting circuit is shown as being energized by a dynamo, the main current is caused to traverse the helix .of a solenoid, the core of which actuates a polechanging switch. By means of this switch the current is directed in one direction or the other through an electro-magnetic helix operating a magnetic clutch, which controls the reversing-gear of a cone-pulley belt-shipper,

and the changes of current in the main circuit are through the agency of this combinar* tion of mechanism enabled to act upon their source, and the current is thus constantly regulated, and the supply of current is caused to uniformlyadjust itself to the demand. If, for example, certain lamps or motors in circuit and operated bythe currentowing in the circuit are cut out, the current is momentarily increased, and the solenoid sucks in the core with increased vigor, the switch operated by the said core directs the current in a given direction through the clutch-helix, and the belt-shipping gear is operated in a direction to lower the speed. The velocity of the driven cone-pulley is thereby reduced, and the dyname-armature driven thereby is correspondingly slowed up, with the final result that its delivery of current is materially lessened, the volume being at once lowered to the required point. So, also, should additional lamps be introduced, the current momentarily weakens, the solenoid-core is pulled Voutward by a retracting force-such as a Weight or springthe pole-changing switch reverses the current through the clutch-helix, the belt-shipper is reversed, and moves in a direction to increase the speed of the driven pulley and dynamo, and the delivered current rapidly rises in proportion to the increased work. When the current traversing the circuit is in exact proportion to the work, the solenoid-core occupies a medium or balancing position, and the-poll-changingswitch controlled thereby occupies also an interme diate position, and practically short-circuits the clu tch-helix. der these circumstances is disengaged from the shipping-ear and the shipper remains in a constant position, the speed of the driven pulley and dynamo being exactly proportioned to the work and the current being normal. In practice the changes are quickly made and the regulator promptly responds to any change in the Work, the solenoid-core, pole-changing switch, belt-shipper, and reversing-gear constantly making slight and brief changes to balance brief and practically inconsequent changes of current.

In another embodiment of my invention the condition `of the work-is caused to exercise The said clutch-helix un- IOO varying degrees of pressure upon a pressuregage or an inclosed diaphragm, which acts through a suitable lever in the manner'of a. By means this manner may be caused to act directly upon the motor or engine immediately performing the work, in this case a pump being shown, and the speed of the motor may without regard to its character be thus modified; or, if the said motor be driven by electricity its speed may be varied by applying the polechanger ,and electro-magnetic clutch to act vupon the driving-pulleys of the dynamo, in

which case the speed of the motor will be varie-'d by increasing orndecreasing the amount of current delivered to it by the dynamo. I prefer, however, the former method in such a case, as being more direct.

The invention consists, first, in an electrical current or speed regulator in whichthe necessary regulation of electrical currents or the adjustment of current -strength, or of power (electric or otherwise) to the work to be performed is accomplished by causing the fluctuations or changes of the electrical current to effect, through suitable mechanism, corresponding changes of speed in driving mechanism, which changes react upon the said current or upon the immediate motive power in such a Way as tocompensate for or to counteract the initial and undesirable character or conditions of current or speed, maintaining a proper and uniform adjustment of current or power to the Work which at any moment is to be er is being performed.

It also consists 1n an apparatus for reguv lating, governing, or adjusting electric currents by causing changes in the said currents to actuate speed-regulating mechanism, whereby the speed of the dynamo, and consequent-ly the electro-motive force, can be varied and regulated independently of the speed of'the prime mover; and this apparatus consists in certain combinations and subcombinationsof mechanism and electrical appliances and circuits more fully specified hereinafter, and comprising a circuit-changing switch actuated by a solenoid included in the circuit and responsive to changes of current occurring therein, a polarized clutch device governed and controlled by the said switch, and cone-pulleys provided with suitable reversing-gear operated by the said clutch, whereby the speed of the driven conepulley may be automatically varied, as required by variations of work.

' It further consists in the special form of electro-magnetic clutch adopted by me and herein described, in which a hollow electromagnet is alternately attracted and repelled `in either direction, being in all cases repelled from one sidewhile it is attracted to the other, and vice versa, whereby the electro-magnetic attraction and repulsion are made to coincide or unite in lthe accomplishment of the work to be done. Y

In the drawings which illustrate and form a part of this specification, Figure l' is a diagram exhibiting the electrical and mechanical arrangements ot the irst embodiment of my invention in its utilization as a current-regulator, the clutch device being in section. Fig. 1n is a detail showing a modified arrangement of thdcone-pulleys, reversing-gear; and shipper, in which the reversing clutch and gear are mounted upon the shipper screw-shaft, instead of upon the shaft of the driven pulley, as in Fig. 1. Fig. 2 is a side view, partly in section, of the pole-changing switch. Fig. 3 comprises a series of diagrams illustrative of the three positionsof the pole-changing or current-reversing switch shown in Fig. 2. Fig. 4 is an enlarged view of the end of the reversing-screw and belt-shipping device, showing means for preventing the shippingnut from being totally disengaged from the said screw; and Fig. 5,' Sheet 2, is a diagram illustrating the embodiment of my invention in an apparatus adapted to directly control the speed of a pump or other machine or motor, and to adjust thesame to the varying character and condition of the work to be done, the said adjustment being, as in other cases, reached through the instrumentality of cone friction-pulleys, wherein the speed ot the driven pulley is varied through the. agency of changes produced in a currentof electricity, in accordance with the varying demands of the work.

I will iirst describe the instrumentalities illustrated by the figures upon Sheet 1.

D represents a dynamo supplying current IIO for an electric-lighting circuit Z, the outgoing and return wires l and 2 being connected The motion of this pulley N ley M, mounted in close proximity, as shown,

this in turn being controlled and actuated or stopped by ordinary fast and loose pulleys P, operated by a belt from any prime motor in the usual way. The friction cone-pulleys are not in contact with one another, but are separated a short space, within which a short endless ring or belt of leather or like material 13 is compressed. The motion of the driving-pulley M is imparted by friction through the instrumentality of this belt to the driven pulley N, and it is obvious that bymoving the said belt toward one end-or the other the speed of the driven pulley may be varied within limits of considerable extent. This type of cone-pulley arrangement or friction-gearing is of course not new, and various means, automatic and otherwise, have been suggested and adapted for the longitudinal movement of the cone-pulley belt 13. I propose to provide mechanism for the automatic traverse of the said belt which shall be operated by the fluctuation of the current in the dynamo-circuit. One wayA to effect this is shown in the drawings. The shafts of the two cone-pulleysare supported in bearings on the brackets or pedestals E, and the shaft w of the lower pulley extends out a suitable distance to one side and carries upon it bevel-wheels H2 and H3, which are keyed or otherwise secured to steel or cast-iron sleeves s2 and s3, these being bored out smoothly and adapted to rotate either upon lor with the pulley-shaft 'r1/ that is, the said shaft w is loosely fitted to rotate within the said sleeves, and the sleeves will not rotate with it unless clutched thereto ina manner well understood. A bevel-wheel H engages with both of the wheels H2 and H3 and participates in the motion of that one of the two which at the moment may be engaged by and moving with the shaft w. This is mounted on a short vertical shaft h2, and is supported in a bracket G. The said short shaft, by means of bevel-gear h and h', is enabled to rotate the shaft of a screw 12, having a belt-shipping nut n, which clasps the belt 13, moving it one direction or the other, and varying the speed of the driven pulley according as the motion of the pulley-shaft w is conveyed to the screw-shaft by the wheels H2 or H3.

I will now describe the apparatus whereby the changes in position of a clutch determining the direction of rotation of the shippernut screw are eifected and controlled by the variation of current in the main circuit. The cast-iron or steel sleeves s2 and s3, to which are secured the bevel-gear H2 and H3, are permanently magnetized, so that both will present like poles to the space between the bevelwheels. I have shown the magnets as presenting their N poles to one another; but it is of course not material, provided that the poles ot the two magnets facing one another are of like character. The central space between the wheels H2 and H3 is iilled up by an electro-magnetic helix V, having a hollow soft-iron core 'u bored true, so that it fits loosely but snugly upon the shaft w'. This is secured to the said shaft by a feather-key v2, so that it necessarily and at all times participates in the motion of the said shaft, but is capable of sliding longitudinally in either direction thereon. The terminals of the helix are led out to conducting-surfaces upon the fianges of the spool, and are included in the electric circuit z by means of brushes or contact-springs b and b', which are connected with the said circuit and which press upon the spool-flan ges. The hollow core of the helix V thus is strongly magnetized when the helix is traversed by the electric current flowing in the circuit z, and its polarity is determined by the direction of the said current. Thus when the current iiows in a given direction through the said helix one end of the hollow core acquires a north magnetic polarity, the other in like manner becominga south pole. Since both of the permanent magnets s2 and s3 are of like polaritysay N-it follows that the pole of the central core, which also is N, will be repelled by the like pole of the permanent magnet nearest to it, while the S pole at the other end will be attracted by the opposite polarity of the permanent magnet on that side, and the result is that the permanent magnet carrying the bevelwheel is compelled by magnetic attraction to participate in the motion of the hollow helix and its core. The drawings show the'central core v as being attracted to and actuating the magnetic sleeve s3, so that if we assume Vthe driven pulley to be moving in the direction of the arrow the nut-shipping screw is caused to move in the same direction, and the nut will move the belt in a right-hand direction and the speed of the driven pulley will be reduced. Suppose, however, that the direction of the current through the helix V be reversed, the polarity of the core 'u will also be reversed, the magnet s3 and the adjacent pole of said core will now be alike, and will vigorously repel each other, while attraction will be set up between the permanent magnet s2 and the adjacent hollow-core pole, and the repulsion at one end co-operating with the attraction at the other the helix V will be shifted sharply over, the wheel HS will cease to move, and the wheel H2 will be compelled to participate in the motion of the shaft w and helix V, and the motion of the screw l2- will be reversed in direction, tending now to move the shipping-nut to the left, and thus to increase the velocity of the driven pulley.

To counteract any tendency of the magnetpoles to'stick when in contact, I prefer to face the ends of the permanent magnets with a very thin plate of copper or brass, whereby sticking, due to residua-ry magnetism is prevented. 1 It will be seen, therefore, that the device I have described is practically an electro-magnetic clutch, to be operated by changes in the direction of current traversing the longitudinally-movable helix. These changes in the direction of the current I eiect by interposing in the electric circuit and between the main circuit and the loop leading to the clutch-helix V an automatic 'currentreversing switch actuated by a solenoid. This is symbolically indicated in the diagram as being adapted to work horizontally.

B is a suitable base-board. S is a solenoid or hollow helix mounted thereon, having an iron plunging-core c pulled constantly in one direction bya counter-spring 7 (which may be adjustable, as by the screw 8) or equivalent weight, and which, when the current IOO IIO

IZO

passes through the helix, is sucked thereinto to a greater or lesser extent, depending upon the strength of the said current. -To one end of the core c is attached a rod o, pivoted to the strap p, uniting the two bars r and s of a double switch U, these moving on pivots 21 and 22. At the free ends of these switch bars are contact-pieces 9 and 10, which slide over a surface g of non-conducting material, into which is let conducting-plates d e f. One of the main circuit-wires 1 is united to one of the solenoid terminals, and the other main wire 2 is connected with the switch-bar s at 22. The remaining solenoid terminal is connected by wire 3 with the other switchbar r at 21. The central switch-plate e is united by the wire 6 with one terminal b of the clutch-helix, and the upper and lower plates d and f are united together bythe wire 4 and vboth by wire 5 with the other terminal b of the said clutch-helix.

In order that the solenoid S may be kept under more perfect control, I prefer to shunt it with an adjustable resistance R, extending from the point 23 through a series of resistances of any suitable character, and by way of the switch 24 to point 26 on wire 3. The switch 24 can be so placed as to include any or all of the resistances in the shunt-circuit, and thereby to regulate the amount of electricity which passes through the solenoid. I have stated that the solenoid'is in 'this instance placed horizontally. It may, however, readily be arranged in several ways, and its'position is not material to my invention. If desired, it may be mounted vertically and the core so arranged that it will be sucked in a downward direction as the helix is energized, and in such a case the core would require to be suspended above and supported and controlled by a counter-weight or spring, whereby it might regain its position when thel helix ceased to attract; or, on the other hand, it might be so arranged that lthe core should be sucked upwardly, in which case its own gravity, preferably modified, however, by a spring, could be employed as a retractor. be associated with thisr solenoid and switch in a manner well understood. Itis also evident that the reversing-switch, solenoid,and clutchhelix can be placed at any point of the circuit where most convenient, and that the several lamps l are shown in circuit between the said switch and the dynamo purely for convenience in illustration.

To prevent any possibility of forcing the traversing or shipping nut against the bearings E, I provide at each end of the shipperscrew, as shown in Fig. 1 and more clearly in Fig. 4, that a portion of the screw-thread shall be removed, and that a helical spring k shall be caused to surround the screw-rod close to the said bearings. By this device the said spring is caused to actlas a buier or elastic cushion and jars are prevented, and, fur- If desired, also, a dash-pot may thermore, a constant pressure is exercised and thus if the nut leaves the screw entirely the spring comes into operation and assists it once more4 to engage the screw as soon as the reverse operation begins.

In Fig. 1* I have shown that the reversinggear and clutch-magnets may be with equal facility placed directly upon the screw-shaft l2 instead of upon the shaft w of the driven pulley N. This view also shows the pulleys M and N reduced in size, as at y, so that by moving the belt 13 over to this point the friction will cease to exist, and the driven pulley may be thereby stopped.

The three plans, 1, 2, and 3, of Fig. 3 indicate the three positions of the solenoid-actuated switch U. That marked 1 shows the switch in its uppermost position, in which a current entering by wire l passes into the clutch-helix by way of the central plate e and out by the wires 5 and 4 and the uppermost plate f. That marked 2 shows 'the switch in the central or intermediate position, the clutch-helix being short-circuited and the current normal. That marked 3 shows the switch in contact with plates e and d, and the current entering the clutch-helix by way of wire 5 and leaving by wire 6.

In the operation of my regulating apparatus let it be understood that the solenoid is so constructed and adjusted that when the current is normal and of proper Working strength the core is sucked thereinto to such a degree that the switch occupies the central posit-ion and the clutch-helix is short-circuited. Under these circumstances the shipper-screw is at rest. If from any cause the current becomes too strong, the solenoid at once becomes more active, the core -is drawn farther in, and the switch assumes the position shown in the drawings. The current is thus directed through the clutch-helix V in a given direction and magnet-izes the hollow core with such a polarity as causes it to be attracted by the magnetic sleeve of that one of the bevel-wheels which will operate the shipper-screw in the direction of decreased speed. The clutch-helix core will at once, by virtue of the said attraction, cause the said wheel to participate in its motion, and the said motion, propagated to the screw, will cause the nut to traverse in the direction adapted to decrease the speed of the driven pulley, and the dynamo being thus driven at a lower rate of speed will develop a lower IOO IIO

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electro-motive force and consequently awith the counter-weight wt.

.the dynamo speed will be accelerated. In

the intermediate position 'f the switch the clutch will tend toward an intermediate position also, its core being practically demagnetized, and in any event it will not retain sufficient strength to hold the wheels. The nut will in consequence remain substantially stationary and the speed constant untilthe next variation of current occurs. In practice brief and rapidly-succeeding changes of solenoid, switch, clutch, and shipper are constantly occurring, which prevent any material or sudden change of speed or current governing the said current and maintaining substantial uniformity therein.

To prevent a continual eifort onthe part of the speed-regulating mechanism to maintain 'a uniform speed while the entire mechanism is being designedly stopped, I provide a switch 41:6,which may be located so as to shortcircuit the clutch-loop only, as shown at co5, or which may be located at m2, so as to shortcircuit the solenoid also. This switch will (when the machine is to be stopped) be turned, and the belt will thus be prevented from accomplishing an unnecessary traverse.

Fig. 5 shows in diagram the adaptation of my invention to a control of the speed of mechanism, the prime motor, as before, maintaining an invariable velocity. In this case D is the dynamo, and D an electromotor in cir'cuit therewith and driven thereby. This electromotor, by the belts 11 and 31 and the cone-pulleys M and N, with their system of i shafting, in turn is made to drive a pump P3,

which may be employed to raise water through the pipe 4l into a tank T. The pump is in this instance the motor or machine immediately performing the work. A pressure-gage o r inclosed diaphragm m is operated by means of the branch pipe 42, and through the vertical rod r2 controls a lever'v, fulcrumed to the upright u and provided The end of the said lever Ir3 actuates a circuit-changing switch Q, and the hammer-headed end thereof 33 is one of the elements of the said circuit-changer, which takes the place and is an equivalent of the current-reversing switch of Fig. l. The speed-regulating mechanism is also identical with that shown in Fig. l, and is in like manner controlled by the' electro-magnetic helix V and the permanentlymagnetic sleeves to which the bevel-wheels IF and H3 are attached.

The electric circuit may be traced as follows: From the plus-pole of the dynamo by Wire 1 to the motor, thence by wire 2 to fixed element 34 of the circuit-changer,thence (in the condition shown) to circuit changer spring 32, and by Way of wire 3 to contactspring D', clutch-helix V, spring b, and Wire 4 to spring 35 of pole-changer Q, movable element 33 thereof, and wire 5 to the minus-pole of dynamo. The extension 33 of the pressure-gage llever is insulated from the main stenl fr, and as it moves upward under increasedpressure raises spring 35 from the fixed element 34, at the same time letting go of the spring 32 and permitting it to make contact with the 'anvil A When the pressure relaxes, the reverse operation is performed, the spring 32 being detached from 34 and depressed-by 33 and the spring 35 released from 33 and allowed to rest on 34.

The operation of this application of my regulator is identical with that already described, except that the said regulation does ynot extend to the dynamo orcurrent, the electric current in this instance being simply utilized as an intermediary, whereby the condition of the work is automatically enabled to control the speed .of the mechanism performing the said work-that is to say, the condition of the work is caused to determine the action of a pole-changer, which controls by 'means of a suitable electro-magnetic device adapted to govern and adjust the speed of the driven pulley, the speed of the prime motor, dynamo, electromotor, and the strength of current remaining substantially unchanged.

I have stated some of the uses and functions of my regulator, and desire to mention, in conclusion, that one of its most important features, in addition to those which are hereinbefore recited, is its capability to automatically rectify and compensate for changes in current or work resulting from changesn the speed of the prime mover. It will be evident that it has a special adaptation to this exigen'cy, and that should the prime motor vary in either a faster or slower direction the regulator, acting through the cone-pulleys and their electro -magneticallyactuated reversing-gear, will in a, brief period of time respond thereto and counteract the said change. My governing apparatus is thus equally eilicient in cases where the variations are in the prime mover, the work remaining the Same as in cases where the variations are chiey in the work and due to external causes, the operation of the prime mover remaining uniform.

Having nowlfully described my invention, I claim l. The hereinbefore-described electric-current and speed regulating apparatus, comprisin ga driving cone-pulley running at a uniformy speed, a driven cone-pulley actuated thereby and driving a dynamo, the velocity thereof being dependent upon the position of a friction-belt interposed between the said pulleys, belt-shipping apparatus comprising a rotat- IOO IIO

' ing screw and a traversing belt-shipping nut,

the said screw being driven by thedriven pulley, vreversing-gear whereby the direction of rotation of the said screw and the longitudinal'traverse of the nut may be at' any point reversed, an electro -magnetic clutch controlling the said reversing-gear, and a reversing-switch operated by asolenoid responsive to changes of current in the main circuit, the said switch being adapted to reverse the said main current through the 'helix 'of Atric regulator or governor, of a system of friclas tion cone-pulleys provided with a rotary screw and traversing-nut belt-shipper, and with suitable reversing-gear for reversing the direction of rotation of the said screw for the purpose of changing or regulating the speed of the driven cone-pulley, of an electro-inagnetic polarizedclutch comprising a hollow helix, a soft-iron hollow core therein feathered upon the shaft of the driven pulley or' shipper-screw and capable of longitudinal movement thereon, andtwo permanently-magnetic sleeves presenting like poles to the two ends of the said core, the said sleevesbeingconnected with the reversing-gears, as described, a main electric circuit, a loop thereofincluding the said hollow helix, and a circuit-changing switch operated by a solenoid'included in the said main circuit and adapted to direct the current in the main circuit through the loop and clutch-helix in either direction or to short-circuit the same, whereby the said clutch-helix and core are made lto move longitudinally upon the shaft to actuate the belt-A shipper, and thereby to vary the speed of the driven pulley responsively to changes in the strength of the main current, substantially as and for the purposes specified.

3. The combination, substantially as hereinbefore described, in an electric .regulating or governing mechanism, of a circ uit-changing or current-reversing switch actuated by a solenoid included in the main electric circuit and responsive to changes occurring therein, a polarized clutch device governed and controlled by the said switch and'responding to reversals of current through its helix, and cone-pulleys provided with suitable reversinggear operated by the said clutch, whereby the speed of the driven cone-pulley may be automatically varied, as required by variations of work.

4. In a bevel-wheel-reversing gear, the combination of the two facing bevel-wheels, each provided with a permanently-magnetized sleeve constituting the hub of said wheel and loosely upon'tthe same shaft between the said v two bevel-wheels and adapted to slide longitudinallyupon the said shaft, the sald magnet being responsive to changes in the direction ot' an electric current and to be attracted by one of the wheel-magnets and repelled by the other, accordingto the direction of the said current through its helix, and thereupon to cause the wheel at any period 'exercising attraction to participate in the motion of the shaft and electro-magnet, substantially as del scribed.

5. The combination, with friction cone-pulleys and belt-shippingdevices therefor, comprisinga belt-shipping nut, a screw traversed thereby and adapted to rotate in either direction, and reversing-gear for the said screw, consisting of bevel-wheels running loose on a working shaft, facing one another and engagin with a third, as shown and described, of a poarized clutch consisting of an electro-magnet having a hollow soft-iron core, which core is keyed to the said working shaft and adapted to slide longitudinally into contact with the face of either bevel-wheel on the same shaft, and of two hollow permanent magnets, each forming the center of one of they said bevelwheels, and both presenting a like poleto the end of the said electro magnet, which is adapted to be repelled by one and attracted by the other, according to the direction of the currentv traversing its helix.

6. The combination, with an electric circuit, a loop thereof, and an electromagnetic helix included in said loop, acting as a clutch for a reversing mechanism, provided with a hollow soft-iron core and adapted to slide on a shaft between similar permanently-.magnetic poles, of a' solenoid in the main circuit, and a current-reversingorcii'cuit-changingswitch actuated b'y said solenoid and adapted to determine the 'direction of the fmain-line current through the loop and clutch-magnet, according to its position,'whereby the said clutchmagnet will be attracted to one side or the other, according to the direction in which the said main-line current traverses its helix, substantially as described. v

-7. The combination, substantially as hereinbefore described, of the cone-pulleys M and N, the automatic belt-shipper therefor, comprising ythe rotary screw 12 and nut n, the said screw being deprived of its threads at a portion of its surface near each end thereof, and a helical spring encircling the said stripped screw ends, for the purpose specified.

8. In an electrical regulator or governor, a main electric circuit, a loop thereof, an electro-magnetic clutch included in said loop and responsive to changes in the direction of the current traversing its helix, a 'pole-changing or current-reversing switch included in the IIO main circuit at the junction therewith ofthe In testimony whereof I have signed my said loop, and determining byits posit-ion the name to this specification, in the presence of 1o direction of the main-circuit currentthrongh two subscribing Witnesses, this 4th day of the said olutch-helimend an actuating device February, 1889.

5 for the said switch responding to Variations HENRY J. CONANT.

in the Work performed by the main current Witnesses: and operating the seid switch in accordance GEO. WILLIS PIERCE.

therewith, snbstantialiy as described herein. JOHN F. MARTIN. 

